Electrical terminal



Sept. 14, 1943. D. H. KING ELECTRICAL TERMINAL Filed Aug. 7, 1942 2Shaets-Sheet 1 FIG. 7

A T TORNE V Sept. 14, 1943., D. H. KING 2,329,471

ELECTRICAL TERMINAL Filed Au 7. 1942 2 Sheets-Sheet 2 F7619 F [6. l0

INVENTOR 0. H. KING A TTORNEV Patented Sept. 14, 1943 UNITED STATESPATENT OFFICE ELECTRICAL TERMINAL Douglas H. King, Short Hills, N. J.,assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y.,a corporation of New York Application August '1, 1942, Serial No.453,953

7 Claims.

This invention relates to electrical terminals and more particularly toelectrical terminals con structed and arranged for mounting in a supportby having a portion of the terminal driven into a recess provided in thesupport.

The object of the invention is to provide a terminal which when driveninto a recess formed in a support of insulating material will remainsecurely anchored in the support.

A feature of the invention resides in the form and construction of oneend portion 01' the terminal.

In the drawings:

Fig. 1 is a view in perspective of one form of the terminal embodyingthe invention;

Fig. 2 is a view, partly in section, of a fragmentary portion of aninsulating support with a' recess formed therein and the lower portion01' the terminal, Fig. 1, placed in the recess;

I Fig. 3 corresponds to'Fig. 2 but shows the terminal driven within therecess so that the terminal is securely anchored in place Fig. 4 is aview in perspective of an insulating support with two terminals of thisinvention secured in place and with one of the terminalsv showing amodification of the invention and" indicating that the terminal may beof either straight or bent iorm;

Fig. 6 shows the lower portion 01 the terminal, Piglet 5, placed in therecess in an insulating sup- P Fig. 7 corresponds to Fig. 6 but showsthe terminal secured in place;

Fig. 8 shows a modified form of the terminal;

Fig. 9 shows the lower end of the terminal, Fig. 8, placed in a recessin a support; and

Fig. 10 corresponds to Fig. 9 but shows the terminal secured in place.

Terminal blocks and other insulating supports for terminals are oftenmade of thermoplastic insulating material such, for instance, as hardrubber. The terminal to be supported in the insulating support is oftenset and held in place in a. mold while insulating material is beingmolded to form the required support. In doing position during-themolding operation.

In some cases inorder to eliminate the necessity of.using jigs orfixtures to hold the terminals in position during the molding oi theinsulating support, recesses have been formed in the insulating supporteither during or after the. molding operation, the recesses beingprovided to receive the terminals. After the insulating support-ismolded and a recess isformedtherein the terminal is driven into therecess and is held in place by frictional engagement of the terminalagainst the walls defining the recess. make it more diiiicult towithdraw the terminal from the recess teeth have been provided on theportion of the terminal entered in the recess, the idea being that theteeth will dig into the walls of the recess. In such arrangements,however, the recess is made smaller than the entered portion of theterminal and when the terminal isbeing driven into place the teeth cuttheir way into the Walls of the recess and form grooves behind themthrough which the teeth may pass when separation of the terminal fromthe insulating support is attempted.

My invention is an improvement in driven-in type terminal structures andarrangements and provides a construction and arrangement which permitsready placing of the terminal in the recess and when the terminal isdriven down within the recess the entered portion of the terminal takessuch form that the terminal remains securely anchored in place.

In Fig. 1 the terminal I which may be made of sheet metal or othersuitable material, is provided with leg members 2 and 3 extending insubstantial parallel spaced relation on opposite sides of an aperture 4formed longitudinally in the lower portion of the terminal. The aperture4 resembles an inverted keyhole but is not entirely closed at the lowerend when the terminal i is originally formed. The lower end of the legmember 2 is provided with a foot 5 which is toed inwardly toward acorresponding foot 6 formed on and extending from the leg member 3. Thefeet 5 and 6 slope downwardly and inwardly toward each other and are inalmost toe-to-toe engagement in Fig. 1. The upp r end of the foot 5 isnarrowed at l and the upper end of the foot 5 is narrowed at 8 to makethe feet more readily bendable at these points. The lower ends of thefeet 5 and 6 are rounded at 9 and i0, respectively, and the outer edgesof the feet5 and 6 are curved at H and I2 for a purpose to be laterexplained. The leg members 2 and 3 are reduced in width at therespective-points l3 and M to make the leg membersmore readily bendableat these In an eflort to points and the outer edges of the leg members 2and 3 are contoured to provide teeth I5 and I5, the teeth I5 and I5 oneach leg member being directed in the direction of the line of thrust ofthe leg member. The advantage provided by this arrangement of the teethwill be subsequently explained. A tapped hole II is provided in theupper portion of the terminal I to receive a screw, not shown, but whichmay be employed in fastening a wire to the terminal.

As shown in Fig. 2 a tapered recess I5 is formed in a support I5 made ofinsulating material, the recess I5 being rectangular in form, therectangular form being longer at the top than at the bottom. The depthof the recess I8 is slightly less than the length of the aperture 4 andthe lower end 25 of the recess is flat. The end walls 2| and 22 of therecess I5 slope inwardly from the top to the bottom. The length of therecess I5 gradually decreases from the top to the bottom and is sodimensioned that when the terminal I is being placed in the recess theteeth I5 and I5 on the leg members 2 and 3 will not cut into the endwalls 2| and 22 until the teeth 1 5 and I5 on the leg members are partway down the recess I5. Since the feet 5 and 5 are not in mutual.engagement when the terminal I is originally formed the leg members 2and 3 may be slightly sprung toward each other as the terminal I isbeing moved to the position shown in Fig. 2, the springing of the legmembers 2 and 3 toward each other being accomplished by the cammingaction of the end walls 2| and 22 against the teeth I5 and I5.

When the terminal I reaches the position shown in Fig. 2 the feet 5 and5 are in toe-to-toe engagement and are in engagement with the lower wall20 of the recess I5. After the terminal I is placed in the recess I8 inthe position shown in Fig. 2 the terminal is driven downwardly in therecess I8 to the position shown in Fig. 3. During this driving-inoperation the feet 5 and 5 bend at the narrowed portions I and 8 andsince the feet 5 and 6 are in toe-to-toe engagement the leg members 2and 3 cannot come closer together. The feet 5 and 5 are moved intosubstantially fiatfoot engagement with the lower wall 20 of recess I8and into the position shown in Fig. 3. In taking this position the feet5 and 5 force the leg members 2 and 3 away from each other so that theteeth I5 and I5 are driven into the end walls 2| and 22 of the recessI5, the leg members 2 and 3 bending at the narrowed portions I3 and I4and so that the aperture 4 shown in Figs. 1 and 2 takes the form of theaperture 23 shown in Fig. 3. The feet 5 and 5 are curved at H and I2,respectively, so that the feet 5 and 6 will rock on the fiat surface ofthe lower wall 2|) of the recess I5 when the terminal I is being drivento final position. The roundedends 9 and I0 permit slight turning up ofthe toe-to-toe engaged portions of feet 5 and 5 and so that the feet 5and 5 when moving to final position pass through a dead center positionrelative to each other and in final position are slightly above the deadcenter position.

The teeth I5 and I5 on each leg member as above mentioned are formed andarranged so that they point in the direction of the line of thrust ofthe leg member. The advantage in this construction and arrangement ofthe teeth I5 and I5 is that when the terminal I is being driven down inthe recess I5 and so that the tooth I5 on leg member 2, for instance,cuts a way for itself in the wall 2| of the recess I8, the tooth I5 incutting a way for itself in the wall 2| will force material from thewall 2| into the valley portion 24 between the teeth I5 and I5 andagainst the upper wall 25 of the tooth I5. forced down by the tooth I5against the upper wall 25 of the tooth I5 and into the valley portion 24serves in some measure to prevent withdrawal of the leg member 2 fromthe recess I5. It will be seen that in orderto withdraw the leg members2 and 3 from the reces I5 it would be necessary to move the leg members2 and 3 toward each other and that this is prevented by the feet 5 and 5which are in toe-to-toe engagement and which would have to be moveddownward through and beyond dead center position before the leg members2 and 3 could come closer together.

Fig. 4 shows a terminal block 25 equippedwvith terminals made inaccordance with this invention, the terminals 21 and 28 having beendriven down within the tapered recess I5 formed in the terminal block25. The terminal 2! may be like the terminal I shown in Figs. 1, 2 and 3and be equipped with a screw 29 in the tapped hole II. The terminal 25may be of like construction but having the outer end portion3|| bentangularly relative to the end portion secured in the block 25.

In the modification shown in Figs. 5, 6 and 7 the terminal 3| follows,in general, the pattern of the terminal I above described and isprovided with leg members 32 and 33 extending in substantially parallelspaced relation on opposite sides of an elongated aperture 34 formedlongitudinally in the lower portion of the terminal. The lower end ofthe leg member 32 is provided with a foot 35 which is toed inwardlytoward a corresponding foot 35 formed on andextending from the legmember 33. The feet 35 and 35 slope downwardly and inwardly toward eachother and are in almost toe-to-toe engagement in Fig. 5. The leg member32 is narrowed at 31, and the leg member 33 is narrowed at 35 to makethe leg members more readily bendable at these points. The lower ends ofthe feet 35 and 35 are rounded at 39 and 45, respectively, and the outeredges of the feet 35 and 35 are curved at 4| and 42. The leg members 32and 33 are reduced in width at the respective points 43 and 44 to makethe leg members more readily bendable at these points, and the outeredges of the leg members 32 and 33 are contoured to provide teeth 45 and45, the teeth 45 and 45 on each leg member being directed toward the topof the terminal. The terminal 3| may be straight as indicated by thedot-dash lines in the figure or may be bent as shown in full line and isprovided with a tapped hole 41 to receive a screw, not shown, but whichmay be used in connecting a wire to the terminal.

In Fig. 6 the terminal 3| is placed in the tapered recess I5 formed in asupport I9 made of insulating material, the recess I8 being of the formdescribed in connection with Figs. 2 and 3 and having its depth slightlyless than the length of the aperture 34. After the terminal 3| is placedin the recess I5, as shown in Fig. 6, and with the feet 35 and 35 inengagement with the lower wall 2|] in the recess I8 and with each other,the terminal 3| is driven downwardly in the recess I8 to the positionshown in Fig. 7. If the terminal 3| is of bent form such as shown infull lines in Fig. 5, 2. lug 45 may be formed on the terminal 3| toserve as an anvil to receive a blow applied to the terminal in drivingthe terminal downwardly in the recess l5. During the driv- The materiala terminal 5| is drivendownwardly m the recess a lng-in operation theleg members 32 and 33 bend to the position shown in Fig. 10. During thisat the narrowed portions 31 and 33; respectively, and the feet 35 and 36are in toe-to-toe engageement and move into substantiallyflat footengagement with 'the lower wall 23 of the recess i3 and into theposition shown in Fig. '7. In taking this position the feet 35 and 36force the leg members 32 and 33 away from each other and so that theteeth 45 and are driven into the end walls 2| and 22 of the recess i3.the leg members 32 and 33 bending slightly outwardly from the narrowedportions 43' and .44 and so that the aperture 33 shown in Figs. 5 and 6takes the form of the aperture 49, shownin Fig. 7. I g

,It will be seen in Fig. 7 that the teeth 45 and 46 driving-in operationthe feet 55 and 56 bend at narrowed portions 51 and 58 and since thefeet 55 and 56 are in toe-to-toe engagement the leg members 52 and-53cannt,come closer together.

' The feet 55 and 56 are moved into substantially flat-foot positionrelative to the lower wall 23 of the recess i8'and'into the positionshown in Fig. 10. In taking this'position the feet 55 and 56 force theleg members 52 and 53 away from each other and so that'the-corners 66are driven into the end walls 2| and 22 of the recess It, the leg havebeen driven into the walls 2| and 22' of the I recess" and that eachtooth 45 inmoving to its final position in the recess "has forced someof the material in the end wall of the recess against the upper portion50 of the tooth 36. Also, that the feet 35 and 36 .in taking theirvfinal position have passedslightly above a dead center condition, andthe leg members 32 and 33 by reason of the position of the feet 35 and36 cannot easily be made to move towardeach'other if an effortis made towithdraw the terminal 3| from'the recess |8. l

In Fig. 8 which shows a modified form of the terminal there are no teethon the leg members of the terminal. The terminal shown in this figurefollows in other respects the general pattern of the terminal I shown inFig. 1. The terminal 5| is provided with leg members 52 and 53 members"52 and 53 bending at the narrowed portions 63 and '64 duringthis'outwardmovement of the leg members.

It win be seen as shown in Fig.1 that the corners 66 shown in Figs. 8and 9 have become obtuse angles 68 thrust rather deeply into the walls2| and 22 of the recess i6 and that the greaterqpor tion of thestraight; outer edge 65 of each leg extending in substantially parallelspaced rela I tion on opposite sides of an aperture 54 formedlongitudinally in the lower portion of the terminal. The lower end oftheleg member 52 is provided with a foot 55 which is toed inwardly toward acorresponding foot 56 formedon and extending from the leg member 53. Thefeet 55 and 56 slope downwardly and inwardly toward each other and arein almost toe-to-toe engagement in Fig. 8. The upper end of the foot 55is narrowed at 51 and the upper end of the foot 56 is narrowed at 58 tomake the feet more readily bendable at these points. The lower ends ofthe feet 55 and 56 are rounded at 59 and 65, respectively, and the outeredges of the feet 55 and 56 are curved at Bi and 62 to permit the feetto rock on the lower end 20 of the recess l8 shown in Figs. 9 and 10.The leg members 52 and 53 are reduced in width at the respective points63 and 64 to make the leg members more readily bendable at these points.The outer edges of the leg members 52 and 53 as above pointed out arenot provided with teeth but are straight, each leg memher having astraight outer edge portion 65 extending to a corner 66 where the legmembers 52 and 53 terminate in the feet 55 and 56, respectively. Atapped hole 61 is provided in the upper portion of the terminal 5| toreceive a screw, not shown but which may be employed in fastening a wireto the terminal.

As shown on Fig. 9, the terminal 5| is placed in atapered recess l8formed in the support |9 member extends into the wall of the taperedrecess i8. Also that the taper of the lower portion of the terminal 5|in its final form is substantially opposite to the form of the recessHi. It would be extremely difficult to remove the termin al 5| from thesupport i9, when the terminal 5| is in the final position shown in Fig.'10, since the leg members 52 and 53 are 'engaged in the walls 2| and 22of the recess I8 and the legmembers52 and 53 are held in this finalposition by th toeto-toe engaged feet 55 and 56 which have-also passedupwardly beyond dead center position.

What is claimed is:

1. An electrical terminal suitable for mounting its leg member by anintegral readily bendable portion, the feet on said leg members beingarranged to engage each other in a toe-to-toe manner and cooperativelyspread said leg members apart when the terminal is driven into therecess, and the feet on said leg members being operable during thedrivin in of said terminal to move through and slightly above a deadcenter condition and so that they will be cooperatin to hold said legmembers in spread apart condition in the recess in said'support and inholding engagement with walls of the recess.

2. An electrical terminal driven into a recess formed in a support ofinsulating material, said terminal comprising a pair of leg members ex--tending in said recess, inwardly toed feet on said leg members engagingthe bottom of said.

recess and engaging each other in a toe-to-toe manner, each of said feetbeing connected to its supporting leg member by a weakened portion whichis bent during the driving in of said terminal. and said feet havingbeen moved upwardly and slightly beyond a dead center condition butstill cooperating to hold said leg members spaced apart in said recessand'in holding engagement with the walls of said recess.

3. An electrical terminal suitable for driving into a recess formed in asupport of insulating material, said terminal comprising a pair of legmembers arranged to enter said recess, a foot on each leg member toeddownwardly and inwardly toward a corresponding foot on the'other legmember, the juncture of each foot and leg member being relatively narrowto make the structure readily bendable at these points, said feet beingarranged to engage the bottom of said recess and to engage each other ina toeto-toe manner when said terminal is-inserted in said recess andsaid feet being arranged to operate in the manner of levers on said legmembers and cooperate to force the lower ends of said leg members awayfrom each other and so that said leg members will be forced into holdingengagement with the walls of said recess and will be maintained inholding engagement with walls of said recess when said terminal isdriven into said recess.

4. An electrical terminal suitable for driving into a recess formed in asupport of insulating material, said terminal comprising a lower portionformed to provide spaced leg members teeth formed on the outer edges ofsaid leg members, said teeth being directed in the line of thrust ofsaid leg members, feet on said leg members extending angularly downwardof said leg members and inwardly toward each other, said feet beingarranged to engage each other in a toeto-toe manner and force said legmembers outwardly within the recess and force said teeth into walls ofthe recess when said terminal is driven into the recess, said feetcooperating to hold said leg members in such' condition that said teethare maintained in holding engagement with the walls of the recess.

5. An electrical terminal suitable for mounting in a support by drivinga portion of the terminal into a recess formed in thesupp rt, saidterminal comprising a lower portion having an elongated aperture formedtherein, a pair of leg members extending in spaced relation and definingsaid aperture, a foot on each leg member sloping downwardly and inwardlytoward a corresponding foot on the other leg member, teeth formed on theouter edge of each leg member, said teeth being directed toward thelower end of said terminal, said feet being readily bendable at thejunctures of said feet with said leg members and being arranged toengage each other in toeto-toe manner and to outwardly thrust said legmembers to project said teeth into the walls of said recess and locksaid leg members in this position when said terminal is driven into saidrecess against the lower wall of said recess.

6. An electrical terminal suitable for mounting in a support by drivinga portion of the terminal into a recess formed in the support, saidterminal comprising a lower portion having an elongated aperture formedtherein, a pair of leg members extending in spaced relation and definingsaid aperture, a foot on each leg member sloping downwardly and inwardlytoward a corresponding foot on the other leg member, said feet beingreadily bendable at the junctures of said feet with said leg members andbeing arranged to engage each other in a toe-to-toe manner and outwardlythrust said leg members into holding engagement with the walls of saidrecess and locksaid leg members against withdrawal from said recess whensaid terminal is driven into said recess and against the lower wall ofsaid recess.

7. An electrical terminal suitable for mounting in a support by drivinga portion of the terminal into a recess formed in the support, saidterminal comprising a lower portion having an elongated aperture formedtherein, a pair of leg members extending in spaced relation and definingsaid aperture, a foot on each leg member sloping downwardly and inwardlytoward a corresponding foot on the other leg member, teeth formed on theouter edge of each leg member, said teeth being directed toward theupper end of said terminal, said feet being readily bendable at thejunctures of said feet with said leg members and being arranged toengage each other in a toeto-toe manner and to outwardly thrust said legmembers to project said teeth into the walls of said recess and locksaid leg members in this position when said terminal is driven into saidrecess and against the lower wall of said recess.

DOUGLAS H.

